Cleave- When a successful attack causes damage has a % chance of attacking a unit next to the one hit.
Whirlwind- Attacks all units in a full circle
Charm- Causes unit to join up with the unit that charmed it. % chance that after combat unit will remain with the unit that charmed it
Walker (ForestWalker, Desert Walker, Jungle Walker etc)- Units in either the tactical or main map will not be visible if they are in their favored terrain
Invisibility/Hide in Shadows- Unit is invisible
Dirge of Doom- Causes enemy units morale to drop
Song of Inspiration- Causes friendly units morale to rise
Entangle- Causes terrain to hold units in place
Sniper- Allows ranged unit to be invisible, fire a missile, and go invisible again
Seige Breaker- Unit can cause damage to city walls, or other defensive terrain
Horse/Worg Master- Additional movement or attacks when riding on a chosen mount.
Immunities- Unit is immune to a specific type of damage (Piercing, Fire, Earth), or progressive based, where Immunity I gives you a 25% chance of ignoring the damage and Immunity II gives you 50%, etc..
Disease- Causes units to lose HP per round and healing spells are not as effective until cured. Continues damage into the main map after tactical battle is finished until it is healed
Incorporeal- Only magic weapons or magical attacks do any damage
Levitate/Fly- Able to get past walls or other defensible positions in order to attack enemies.
Berserker or Rage- Attack and Hp's rise while Defense drops
Inspired leader- Raises friendly stats. Could either be variations of this such as Charismatic leader (where all Charisma is buffed), or a progressive based version
where at level one you get one stat increase (HP +5) at level 2 you get 2 stats (HP +5 and Attack +2), level 3, etc...
Swallow Whole- Unit is destroyed in X number of rounds unless unit is killed..Gives benefit of extra HP's or some additional powers based on what unit was swallowed.
Mimic--Allows you to mimic a power of another creature you are fighting
Shapechange--Makes your unit look either like another unit showing false info, or actually allows you to mimic that creature completely.
Putrid Stench- Nearby creaturs suffer a penalty to attack/damage and defense.
Cone of Vomit- Causes minor acidic damage, and lowers defense of creature...perhaps has a chance to cause additional effect (blindness, slow, sickness)
Armor Master- Brings up the defense of the unit, can also scale such as Armor master I gives you +2 to Def while Armor Master II gives you +4 to defense
Weapons Master- Same as above but uses attack/damage Values
Sacrifice/Retributive Strike--Causes unit to die a violent death, but causes major damage to all nearby units